drivers/net/phy/bcm-phy-lib.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2015-2017 Broadcom
  */

 #include "bcm-phy-lib.h"
 #include <linux/brcmphy.h>
 #include <linux/export.h>
 #include <linux/mdio.h>
 #include <linux/module.h>
 #include <linux/phy.h>
 #include <linux/ethtool.h>

 #define MII_BCM_CHANNEL_WIDTH     0x2000
 #define BCM_CL45VEN_EEE_ADV       0x3c

 int bcm_phy_write_exp(struct phy_device *phydev, u16 reg, u16 val)
 {
 	int rc;

 	rc = phy_write(phydev, MII_BCM54XX_EXP_SEL, reg);
 	if (rc < 0)
 		return rc;

 	return phy_write(phydev, MII_BCM54XX_EXP_DATA, val);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_write_exp);

 int bcm_phy_read_exp(struct phy_device *phydev, u16 reg)
 {
 	int val;

 	val = phy_write(phydev, MII_BCM54XX_EXP_SEL, reg);
 	if (val < 0)
 		return val;

 	val = phy_read(phydev, MII_BCM54XX_EXP_DATA);

 	/* Restore default value.  It's O.K. if this write fails. */
 	phy_write(phydev, MII_BCM54XX_EXP_SEL, 0);

 	return val;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_read_exp);

 int bcm54xx_auxctl_read(struct phy_device *phydev, u16 regnum)
 {
 	/* The register must be written to both the Shadow Register Select and
 	 * the Shadow Read Register Selector
 	 */
 	phy_write(phydev, MII_BCM54XX_AUX_CTL, MII_BCM54XX_AUXCTL_SHDWSEL_MASK |
 		  regnum << MII_BCM54XX_AUXCTL_SHDWSEL_READ_SHIFT);
 	return phy_read(phydev, MII_BCM54XX_AUX_CTL);
 }
 EXPORT_SYMBOL_GPL(bcm54xx_auxctl_read);

 int bcm54xx_auxctl_write(struct phy_device *phydev, u16 regnum, u16 val)
 {
 	return phy_write(phydev, MII_BCM54XX_AUX_CTL, regnum | val);
 }
 EXPORT_SYMBOL(bcm54xx_auxctl_write);

 int bcm_phy_write_misc(struct phy_device *phydev,
 		       u16 reg, u16 chl, u16 val)
 {
 	int rc;
 	int tmp;

 	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL,
 		       MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
 	if (rc < 0)
 		return rc;

 	tmp = phy_read(phydev, MII_BCM54XX_AUX_CTL);
 	tmp |= MII_BCM54XX_AUXCTL_ACTL_SMDSP_ENA;
 	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL, tmp);
 	if (rc < 0)
 		return rc;

 	tmp = (chl * MII_BCM_CHANNEL_WIDTH) | reg;
 	rc = bcm_phy_write_exp(phydev, tmp, val);

 	return rc;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_write_misc);

 int bcm_phy_read_misc(struct phy_device *phydev,
 		      u16 reg, u16 chl)
 {
 	int rc;
 	int tmp;

 	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL,
 		       MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
 	if (rc < 0)
 		return rc;

 	tmp = phy_read(phydev, MII_BCM54XX_AUX_CTL);
 	tmp |= MII_BCM54XX_AUXCTL_ACTL_SMDSP_ENA;
 	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL, tmp);
 	if (rc < 0)
 		return rc;

 	tmp = (chl * MII_BCM_CHANNEL_WIDTH) | reg;
 	rc = bcm_phy_read_exp(phydev, tmp);

 	return rc;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_read_misc);

 int bcm_phy_ack_intr(struct phy_device *phydev)
 {
 	int reg;

 	/* Clear pending interrupts.  */
 	reg = phy_read(phydev, MII_BCM54XX_ISR);
 	if (reg < 0)
 		return reg;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_ack_intr);

 int bcm_phy_config_intr(struct phy_device *phydev)
 {
 	int reg;

 	reg = phy_read(phydev, MII_BCM54XX_ECR);
 	if (reg < 0)
 		return reg;

 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
 		reg &= ~MII_BCM54XX_ECR_IM;
 	else
 		reg |= MII_BCM54XX_ECR_IM;

 	return phy_write(phydev, MII_BCM54XX_ECR, reg);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_config_intr);

 int bcm_phy_read_shadow(struct phy_device *phydev, u16 shadow)
 {
 	phy_write(phydev, MII_BCM54XX_SHD, MII_BCM54XX_SHD_VAL(shadow));
 	return MII_BCM54XX_SHD_DATA(phy_read(phydev, MII_BCM54XX_SHD));
 }
 EXPORT_SYMBOL_GPL(bcm_phy_read_shadow);

 int bcm_phy_write_shadow(struct phy_device *phydev, u16 shadow,
 			 u16 val)
 {
 	return phy_write(phydev, MII_BCM54XX_SHD,
 			 MII_BCM54XX_SHD_WRITE |
 			 MII_BCM54XX_SHD_VAL(shadow) |
 			 MII_BCM54XX_SHD_DATA(val));
 }
 EXPORT_SYMBOL_GPL(bcm_phy_write_shadow);

 int bcm_phy_enable_apd(struct phy_device *phydev, bool dll_pwr_down)
 {
 	int val;

 	if (dll_pwr_down) {
 		val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR3);
 		if (val < 0)
 			return val;

 		val |= BCM54XX_SHD_SCR3_DLLAPD_DIS;
 		bcm_phy_write_shadow(phydev, BCM54XX_SHD_SCR3, val);
 	}

 	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_APD);
 	if (val < 0)
 		return val;

 	/* Clear APD bits */
 	val &= BCM_APD_CLR_MASK;

 	if (phydev->autoneg == AUTONEG_ENABLE)
 		val |= BCM54XX_SHD_APD_EN;
 	else
 		val |= BCM_NO_ANEG_APD_EN;

 	/* Enable energy detect single link pulse for easy wakeup */
 	val |= BCM_APD_SINGLELP_EN;

 	/* Enable Auto Power-Down (APD) for the PHY */
 	return bcm_phy_write_shadow(phydev, BCM54XX_SHD_APD, val);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_enable_apd);

 int bcm_phy_set_eee(struct phy_device *phydev, bool enable)
 {
 	int val;

 	/* Enable EEE at PHY level */
 	val = phy_read_mmd(phydev, MDIO_MMD_AN, BRCM_CL45VEN_EEE_CONTROL);
 	if (val < 0)
 		return val;

 	if (enable)
 		val |= LPI_FEATURE_EN | LPI_FEATURE_EN_DIG1000X;
 	else
 		val &= ~(LPI_FEATURE_EN | LPI_FEATURE_EN_DIG1000X);

 	phy_write_mmd(phydev, MDIO_MMD_AN, BRCM_CL45VEN_EEE_CONTROL, (u32)val);

 	/* Advertise EEE */
 	val = phy_read_mmd(phydev, MDIO_MMD_AN, BCM_CL45VEN_EEE_ADV);
 	if (val < 0)
 		return val;

 	if (enable)
 		val |= (MDIO_EEE_100TX | MDIO_EEE_1000T);
 	else
 		val &= ~(MDIO_EEE_100TX | MDIO_EEE_1000T);

 	phy_write_mmd(phydev, MDIO_MMD_AN, BCM_CL45VEN_EEE_ADV, (u32)val);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_set_eee);

 int bcm_phy_downshift_get(struct phy_device *phydev, u8 *count)
 {
 	int val;

 	val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
 	if (val < 0)
 		return val;

 	/* Check if wirespeed is enabled or not */
 	if (!(val & MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN)) {
 		*count = DOWNSHIFT_DEV_DISABLE;
 		return 0;
 	}

 	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
 	if (val < 0)
 		return val;

 	/* Downgrade after one link attempt */
 	if (val & BCM54XX_SHD_SCR2_WSPD_RTRY_DIS) {
 		*count = 1;
 	} else {
 		/* Downgrade after configured retry count */
 		val >>= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
 		val &= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK;
 		*count = val + BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(bcm_phy_downshift_get);

 int bcm_phy_downshift_set(struct phy_device *phydev, u8 count)
 {
 	int val = 0, ret = 0;

 	/* Range check the number given */
 	if (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET >
 	    BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK &&
 	    count != DOWNSHIFT_DEV_DEFAULT_COUNT) {
 		return -ERANGE;
 	}

 	val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
 	if (val < 0)
 		return val;

 	/* Se the write enable bit */
 	val |= MII_BCM54XX_AUXCTL_MISC_WREN;

 	if (count == DOWNSHIFT_DEV_DISABLE) {
 		val &= ~MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
 		return bcm54xx_auxctl_write(phydev,
 					    MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
 					    val);
 	} else {
 		val |= MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
 		ret = bcm54xx_auxctl_write(phydev,
 					   MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
 					   val);
 		if (ret < 0)
 			return ret;
 	}

 	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
 	val &= ~(BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK <<
 		 BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT |
 		 BCM54XX_SHD_SCR2_WSPD_RTRY_DIS);

 	switch (count) {
 	case 1:
 		val |= BCM54XX_SHD_SCR2_WSPD_RTRY_DIS;
 		break;
 	case DOWNSHIFT_DEV_DEFAULT_COUNT:
 		val |= 1 << BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
 		break;
 	default:
 		val |= (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET) <<
 			BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
 		break;
 	}

 	return bcm_phy_write_shadow(phydev, BCM54XX_SHD_SCR2, val);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_downshift_set);

 struct bcm_phy_hw_stat {
 	const char *string;
 	u8 reg;
 	u8 shift;
 	u8 bits;
 };

 /* Counters freeze at either 0xffff or 0xff, better than nothing */
 static const struct bcm_phy_hw_stat bcm_phy_hw_stats[] = {
 	{ "phy_receive_errors", MII_BRCM_CORE_BASE12, 0, 16 },
 	{ "phy_serdes_ber_errors", MII_BRCM_CORE_BASE13, 8, 8 },
 	{ "phy_false_carrier_sense_errors", MII_BRCM_CORE_BASE13, 0, 8 },
 	{ "phy_local_rcvr_nok", MII_BRCM_CORE_BASE14, 8, 8 },
 	{ "phy_remote_rcv_nok", MII_BRCM_CORE_BASE14, 0, 8 },
 };

 int bcm_phy_get_sset_count(struct phy_device *phydev)
 {
 	return ARRAY_SIZE(bcm_phy_hw_stats);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_get_sset_count);

 void bcm_phy_get_strings(struct phy_device *phydev, u8 *data)
 {
 	unsigned int i;

 	for (i = 0; i < ARRAY_SIZE(bcm_phy_hw_stats); i++)
 		strlcpy(data + i * ETH_GSTRING_LEN,
 			bcm_phy_hw_stats[i].string, ETH_GSTRING_LEN);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_get_strings);

 /* Caller is supposed to provide appropriate storage for the library code to
  * access the shadow copy
  */
 static u64 bcm_phy_get_stat(struct phy_device *phydev, u64 *shadow,
 			    unsigned int i)
 {
 	struct bcm_phy_hw_stat stat = bcm_phy_hw_stats[i];
 	int val;
 	u64 ret;

 	val = phy_read(phydev, stat.reg);
 	if (val < 0) {
 		ret = U64_MAX;
 	} else {
 		val >>= stat.shift;
 		val = val & ((1 << stat.bits) - 1);
 		shadow[i] += val;
 		ret = shadow[i];
 	}

 	return ret;
 }

 void bcm_phy_get_stats(struct phy_device *phydev, u64 *shadow,
 		       struct ethtool_stats *stats, u64 *data)
 {
 	unsigned int i;

 	for (i = 0; i < ARRAY_SIZE(bcm_phy_hw_stats); i++)
 		data[i] = bcm_phy_get_stat(phydev, shadow, i);
 }
 EXPORT_SYMBOL_GPL(bcm_phy_get_stats);

 MODULE_DESCRIPTION("Broadcom PHY Library");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Broadcom Corporation");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2015-2017 Broadcom
	*/

	#include "bcm-phy-lib.h"
	#include <linux/brcmphy.h>
	#include <linux/export.h>
	#include <linux/mdio.h>
	#include <linux/module.h>
	#include <linux/phy.h>
	#include <linux/ethtool.h>

	#define MII_BCM_CHANNEL_WIDTH 0x2000
	#define BCM_CL45VEN_EEE_ADV 0x3c

	int bcm_phy_write_exp(struct phy_device *phydev, u16 reg, u16 val)
	{
	int rc;

	rc = phy_write(phydev, MII_BCM54XX_EXP_SEL, reg);
	if (rc < 0)
	return rc;

	return phy_write(phydev, MII_BCM54XX_EXP_DATA, val);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_write_exp);

	int bcm_phy_read_exp(struct phy_device *phydev, u16 reg)
	{
	int val;

	val = phy_write(phydev, MII_BCM54XX_EXP_SEL, reg);
	if (val < 0)
	return val;

	val = phy_read(phydev, MII_BCM54XX_EXP_DATA);

	/* Restore default value. It's O.K. if this write fails. */
	phy_write(phydev, MII_BCM54XX_EXP_SEL, 0);

	return val;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_read_exp);

	int bcm54xx_auxctl_read(struct phy_device *phydev, u16 regnum)
	{
	/* The register must be written to both the Shadow Register Select and
	* the Shadow Read Register Selector
	*/
	phy_write(phydev, MII_BCM54XX_AUX_CTL, MII_BCM54XX_AUXCTL_SHDWSEL_MASK \|
	regnum << MII_BCM54XX_AUXCTL_SHDWSEL_READ_SHIFT);
	return phy_read(phydev, MII_BCM54XX_AUX_CTL);
	}
	EXPORT_SYMBOL_GPL(bcm54xx_auxctl_read);

	int bcm54xx_auxctl_write(struct phy_device *phydev, u16 regnum, u16 val)
	{
	return phy_write(phydev, MII_BCM54XX_AUX_CTL, regnum \| val);
	}
	EXPORT_SYMBOL(bcm54xx_auxctl_write);

	int bcm_phy_write_misc(struct phy_device *phydev,
	u16 reg, u16 chl, u16 val)
	{
	int rc;
	int tmp;

	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL,
	MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
	if (rc < 0)
	return rc;

	tmp = phy_read(phydev, MII_BCM54XX_AUX_CTL);
	tmp \|= MII_BCM54XX_AUXCTL_ACTL_SMDSP_ENA;
	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL, tmp);
	if (rc < 0)
	return rc;

	tmp = (chl * MII_BCM_CHANNEL_WIDTH) \| reg;
	rc = bcm_phy_write_exp(phydev, tmp, val);

	return rc;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_write_misc);

	int bcm_phy_read_misc(struct phy_device *phydev,
	u16 reg, u16 chl)
	{
	int rc;
	int tmp;

	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL,
	MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
	if (rc < 0)
	return rc;

	tmp = phy_read(phydev, MII_BCM54XX_AUX_CTL);
	tmp \|= MII_BCM54XX_AUXCTL_ACTL_SMDSP_ENA;
	rc = phy_write(phydev, MII_BCM54XX_AUX_CTL, tmp);
	if (rc < 0)
	return rc;

	tmp = (chl * MII_BCM_CHANNEL_WIDTH) \| reg;
	rc = bcm_phy_read_exp(phydev, tmp);

	return rc;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_read_misc);

	int bcm_phy_ack_intr(struct phy_device *phydev)
	{
	int reg;

	/* Clear pending interrupts. */
	reg = phy_read(phydev, MII_BCM54XX_ISR);
	if (reg < 0)
	return reg;

	return 0;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_ack_intr);

	int bcm_phy_config_intr(struct phy_device *phydev)
	{
	int reg;

	reg = phy_read(phydev, MII_BCM54XX_ECR);
	if (reg < 0)
	return reg;

	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
	reg &= ~MII_BCM54XX_ECR_IM;
	else
	reg \|= MII_BCM54XX_ECR_IM;

	return phy_write(phydev, MII_BCM54XX_ECR, reg);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_config_intr);

	int bcm_phy_read_shadow(struct phy_device *phydev, u16 shadow)
	{
	phy_write(phydev, MII_BCM54XX_SHD, MII_BCM54XX_SHD_VAL(shadow));
	return MII_BCM54XX_SHD_DATA(phy_read(phydev, MII_BCM54XX_SHD));
	}
	EXPORT_SYMBOL_GPL(bcm_phy_read_shadow);

	int bcm_phy_write_shadow(struct phy_device *phydev, u16 shadow,
	u16 val)
	{
	return phy_write(phydev, MII_BCM54XX_SHD,
	MII_BCM54XX_SHD_WRITE \|
	MII_BCM54XX_SHD_VAL(shadow) \|
	MII_BCM54XX_SHD_DATA(val));
	}
	EXPORT_SYMBOL_GPL(bcm_phy_write_shadow);

	int bcm_phy_enable_apd(struct phy_device *phydev, bool dll_pwr_down)
	{
	int val;

	if (dll_pwr_down) {
	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR3);
	if (val < 0)
	return val;

	val \|= BCM54XX_SHD_SCR3_DLLAPD_DIS;
	bcm_phy_write_shadow(phydev, BCM54XX_SHD_SCR3, val);
	}

	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_APD);
	if (val < 0)
	return val;

	/* Clear APD bits */
	val &= BCM_APD_CLR_MASK;

	if (phydev->autoneg == AUTONEG_ENABLE)
	val \|= BCM54XX_SHD_APD_EN;
	else
	val \|= BCM_NO_ANEG_APD_EN;

	/* Enable energy detect single link pulse for easy wakeup */
	val \|= BCM_APD_SINGLELP_EN;

	/* Enable Auto Power-Down (APD) for the PHY */
	return bcm_phy_write_shadow(phydev, BCM54XX_SHD_APD, val);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_enable_apd);

	int bcm_phy_set_eee(struct phy_device *phydev, bool enable)
	{
	int val;

	/* Enable EEE at PHY level */
	val = phy_read_mmd(phydev, MDIO_MMD_AN, BRCM_CL45VEN_EEE_CONTROL);
	if (val < 0)
	return val;

	if (enable)
	val \|= LPI_FEATURE_EN \| LPI_FEATURE_EN_DIG1000X;
	else
	val &= ~(LPI_FEATURE_EN \| LPI_FEATURE_EN_DIG1000X);

	phy_write_mmd(phydev, MDIO_MMD_AN, BRCM_CL45VEN_EEE_CONTROL, (u32)val);

	/* Advertise EEE */
	val = phy_read_mmd(phydev, MDIO_MMD_AN, BCM_CL45VEN_EEE_ADV);
	if (val < 0)
	return val;

	if (enable)
	val \|= (MDIO_EEE_100TX \| MDIO_EEE_1000T);
	else
	val &= ~(MDIO_EEE_100TX \| MDIO_EEE_1000T);

	phy_write_mmd(phydev, MDIO_MMD_AN, BCM_CL45VEN_EEE_ADV, (u32)val);

	return 0;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_set_eee);

	int bcm_phy_downshift_get(struct phy_device phydev, u8 count)
	{
	int val;

	val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
	if (val < 0)
	return val;

	/* Check if wirespeed is enabled or not */
	if (!(val & MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN)) {
	*count = DOWNSHIFT_DEV_DISABLE;
	return 0;
	}

	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
	if (val < 0)
	return val;

	/* Downgrade after one link attempt */
	if (val & BCM54XX_SHD_SCR2_WSPD_RTRY_DIS) {
	*count = 1;
	} else {
	/* Downgrade after configured retry count */
	val >>= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
	val &= BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK;
	*count = val + BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(bcm_phy_downshift_get);

	int bcm_phy_downshift_set(struct phy_device *phydev, u8 count)
	{
	int val = 0, ret = 0;

	/* Range check the number given */
	if (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET >
	BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK &&
	count != DOWNSHIFT_DEV_DEFAULT_COUNT) {
	return -ERANGE;
	}

	val = bcm54xx_auxctl_read(phydev, MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
	if (val < 0)
	return val;

	/* Se the write enable bit */
	val \|= MII_BCM54XX_AUXCTL_MISC_WREN;

	if (count == DOWNSHIFT_DEV_DISABLE) {
	val &= ~MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
	return bcm54xx_auxctl_write(phydev,
	MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
	val);
	} else {
	val \|= MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN;
	ret = bcm54xx_auxctl_write(phydev,
	MII_BCM54XX_AUXCTL_SHDWSEL_MISC,
	val);
	if (ret < 0)
	return ret;
	}

	val = bcm_phy_read_shadow(phydev, BCM54XX_SHD_SCR2);
	val &= ~(BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_MASK <<
	BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT \|
	BCM54XX_SHD_SCR2_WSPD_RTRY_DIS);

	switch (count) {
	case 1:
	val \|= BCM54XX_SHD_SCR2_WSPD_RTRY_DIS;
	break;
	case DOWNSHIFT_DEV_DEFAULT_COUNT:
	val \|= 1 << BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
	break;
	default:
	val \|= (count - BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_OFFSET) <<
	BCM54XX_SHD_SCR2_WSPD_RTRY_LMT_SHIFT;
	break;
	}

	return bcm_phy_write_shadow(phydev, BCM54XX_SHD_SCR2, val);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_downshift_set);

	struct bcm_phy_hw_stat {
	const char *string;
	u8 reg;
	u8 shift;
	u8 bits;
	};

	/* Counters freeze at either 0xffff or 0xff, better than nothing */
	static const struct bcm_phy_hw_stat bcm_phy_hw_stats[] = {
	{ "phy_receive_errors", MII_BRCM_CORE_BASE12, 0, 16 },
	{ "phy_serdes_ber_errors", MII_BRCM_CORE_BASE13, 8, 8 },
	{ "phy_false_carrier_sense_errors", MII_BRCM_CORE_BASE13, 0, 8 },
	{ "phy_local_rcvr_nok", MII_BRCM_CORE_BASE14, 8, 8 },
	{ "phy_remote_rcv_nok", MII_BRCM_CORE_BASE14, 0, 8 },
	};

	int bcm_phy_get_sset_count(struct phy_device *phydev)
	{
	return ARRAY_SIZE(bcm_phy_hw_stats);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_get_sset_count);

	void bcm_phy_get_strings(struct phy_device phydev, u8 data)
	{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(bcm_phy_hw_stats); i++)
	strlcpy(data + i * ETH_GSTRING_LEN,
	bcm_phy_hw_stats[i].string, ETH_GSTRING_LEN);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_get_strings);

	/* Caller is supposed to provide appropriate storage for the library code to
	* access the shadow copy
	*/
	static u64 bcm_phy_get_stat(struct phy_device phydev, u64 shadow,
	unsigned int i)
	{
	struct bcm_phy_hw_stat stat = bcm_phy_hw_stats[i];
	int val;
	u64 ret;

	val = phy_read(phydev, stat.reg);
	if (val < 0) {
	ret = U64_MAX;
	} else {
	val >>= stat.shift;
	val = val & ((1 << stat.bits) - 1);
	shadow[i] += val;
	ret = shadow[i];
	}

	return ret;
	}

	void bcm_phy_get_stats(struct phy_device phydev, u64 shadow,
	struct ethtool_stats stats, u64 data)
	{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(bcm_phy_hw_stats); i++)
	data[i] = bcm_phy_get_stat(phydev, shadow, i);
	}
	EXPORT_SYMBOL_GPL(bcm_phy_get_stats);

	MODULE_DESCRIPTION("Broadcom PHY Library");
	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Broadcom Corporation");